1. Field of the Invention
Embodiments of the invention relate to a stereoscopic image display and a method for driving the same.
2. Discussion of the Related Art
A stereoscopic image display is classified into a display using a stereoscopic technique and a display using an autostereoscopic technique.
The stereoscopic technique, which uses a parallax image between left and right eyes of a user with a high stereoscopic effect, includes a glasses type method and a non-glasses type method, both of which have been put on the market. In the glasses type method, the parallax image between the left and right eyes is displayed on a direct-view display or a projector through a change in a polarization direction of the left and right parallax image or in a time-division manner, and thus a stereoscopic image is implemented using polarization glasses or shutter glasses. In the non-glasses type method, an optical axis of the parallax image between the left and right eyes is generally separated using an optical plate such as a parallax barrier and a lenticular lens, and thus the stereoscopic image is implemented.
In a stereoscopic image display using polarization glasses, an active retarder cell has to be attached to a display element. The active retarder cell includes a liquid crystal layer and electrodes for applying an electric field to the liquid crystal layer. The active retarder cell electrically controls birefringent properties of the liquid crystal layer, thereby converting polarization characteristic of light coming from the display element. For example, when a left eye image is displayed on the display element, the active retarder cell converts polarization characteristic of light coming from the display element into a first polarization. Further, when a right eye image is displayed on the display element, the active retarder cell converts the polarization characteristic of the light coming from the display element into a second polarization. The polarization glasses include a left eye polarization filter transmitting only light having the first polarization and a right eye polarization filter transmitting only light having the second polarization. Thus, the user wearing the polarization glasses views the left eye image through the left eye polarization filter and views the right eye image through the right eye polarization filter in the time-division manner. Namely, the user wearing the polarization glasses may view the stereoscopic image.
The stereoscopic image display using the polarization glasses addresses data of the left eye image or data of the right eye image to the display element, and at the same time, scans the active retarder cell without considering a response delay time between the display element and the active retarder cell. Thus, when the stereoscopic image display using the polarization glasses uses a liquid crystal display element having slow response characteristic, a crosstalk, in which the user views doubled image by leaking part of the left eye image into the right eye image and vice versa, may be generated. Further, the image quality of the stereoscopic image display may be reduced because a luminance varies depending on a location of the liquid crystal display element.
A stereoscopic image display using shutter glasses does not require the active retarder cell. The shutter glasses include a left eye shutter and a right eye shutter, each of which electrically controls birefringent properties of liquid crystals. When a left eye image is displayed on the display element, only the left eye shutter is open. When a right eye image is displayed on the display element, only the right eye shutter is open. Thus, the user wearing the shutter glasses views the left eye image through the left eye shutter and views the right eye image through the right eye shutter in the time-division manner. Namely, the user wearing the shutter glasses may view the stereoscopic image.
The user wearing the polarization glasses cannot view the stereoscopic image through the stereoscopic image display not having the active retarder cell. Further, the user wearing the shutter glasses cannot view the stereoscopic image through the stereoscopic image display having the active retarder cell.